1. Field of the Invention
This invention relates to surgical methods and apparatus in general, and more particularly to surgical methods and apparatus for fusing spinal vertebral bodies.
2. Brief Description of the Related Art
Disc herniation is a condition in which a spinal disc bulges from between two vertebral bodies and impinges on adjacent nerves, thereby causing pain. In some cases, non-operative procedures such as bed rest, medication, lifestyle modifications, exercise, physical therapy, chiropractic care and steroid injections may suffice. However, in other cases, surgical intervention may be necessary. In cases where surgical intervention is prescribed, spinal vertebral body fusion may be desirable, i.e., the spine may have deteriorated so much that adjacent vertebral bodies must be fused together.
Spinal fixation is the current standard of care for surgically treating disc herniation in patients who have chronic pain and who have, or are likely to develop, associated spinal instability. Spinal fixation procedures are intended to relieve impingement on nerves by removing the portion of the disc or bone, or both, responsible for compressing the neural structures and destabilizing the spine. The excised disc or bone is replaced with one or more intervertebral implants, or spacers, placed between adjacent vertebral bodies. These implants stabilize the adjacent vertebral bodies relative to one another so that the two vertebral bodies can fuse together.
One problem with spinal fixation is that the surgeon must make incisions on both sides of the spine. This lengthens the time required to perform an operation and it lengthens the patient's recovery time.
However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the art how conventional surgical procedures could be improved.